1. Field of the Invention
The present invention relates to a semiconductor device constituted by a combination of substrates.
2. Description of the Related Art
U.S. Pat. No. 6,519,075,B2 discloses a technique that connects an electrostatically driven MEMS mirror array obtained by processing a semiconductor substrate to connection pads of another substrate provided with an actuator electrode by use of a solder ball (solder bump). FIG. 13 shows a semiconductor device manufactured in such a manner.
This semiconductor device has a mirror layer 20 and an actuator layer 23. The mirror layer 20 has surrounding frames 22, and gimbaled mirrors 21 allowed to incline with respect to the surrounding frames 22. On the other hand, the actuator layer 23 has actuator electrodes 24 to actuate the mirrors 21. The mirror layer 20 and the actuator layer 23 both have metallization regions 25, and the metallization regions 25 of the mirror layer 20 and the metallization regions 25 of the actuator layer 23 are bonded by the solder balls 26.